Electric switch



L. LUDWIG ELECT'RIC SWITCH Sept. 14, 1937.

Filed May 20, 1935 INVENTOR. l 0 u/ s L 1/ a w/y TTORNEYS.

Patented Sept. 14, 1937 ELECTRIC SWITCH ,Louis Ludwig,

Application May 20,

3 Claims.

This invention relates to electric switches of the type which is usedfor making contact when a door, drawer or similar object is opened.

I am aware that switches have formerly been 5 made in which a lever,engaged and lifted by a door or drawer, closes the switch; Such switchesare objectionablehowever, in that, it frequently happens that if theobject on which they are'employed is only partly opened and then closedagain, 'so that the lever does not have an opportunity to go through itswhole cycle of movements, the lever is caught by the rearward movementof the object, so that the switch is broken or so bent and distorted asto render it useless.

The main object of the present invention is to overcome this defect.Another object is to provide a switch of this type in which a moreperfect contact is made between the switch members. A further object isto provide a switch of simple and strong construction, which can beattached to any object where it may be needed with a mini mumexpenditure of labor, and which can be manufactured at a comparativelylow price.

These and various other objects and advantages will be readilyunderstood from the following description and from the accompanyingdrawing of preferred embodiments of the invention, in which, however,modifications may be made without departing from the scope of theappended claims. In the drawing Fig. 1 is a side elevation of theimproved switch,

Fig. 2, another side elevation shown with the switch mechanism closed,

Fig. 3, still another side elevation showing'the switch mechanism in adifferent position,

Fig. 4, a plan View,

Fig. 5, a side elevation of a slightly modified switch,

Fig. 6, another side elevation of the switch shown in Fig. 5, and

Fig. 7, a rear view of Fig. 5.

Referring first to Figs. 1 to 4 inclusive, the device consists of abracket 10, at the outer end of which a link II is hinged. This link hasan upwardly extending arm l2. Another link l3, having another upwardlyextending arm I, is hinged to the lower end of link H. A contact bladeI5 is secured to a piece of insulating material IB, which is in turnsecured to the bracket, so as to insulate it from the contact blade. Theedge of a door, drawer or other swinging or sliding objects on which theswitch may be used, is indicated at A.

The switch operates in the following manner: The bracket is securedabove the door by means Brooklyn, N. 1935, Serial No. 22,375 (Cl.200-54) ofscrews or other means passed holes ll. If the door'A is movedin [OFFI through the the direction indicated by the arro'w in Fig. 1until it engages the link I3; the link will be moved until the arm itengages on link ll, after which both of the links will be lifted. As thedoor keeps moving in the direction indicated, the links will be lifted,

as shown at Fig. 2, until the arm I2 contacts with the contact blade [5and thus closes the electric circuit. the door continues in thedirection indicated bythe arrow, the links will drop behind the door andthus again break the circuit. When the door is moved in the oppositedirection, as

when being closed, the links are folded up and allow the door to passwithout closing the circuit. Finally after the door is completely closedthe links will again assume the normal or inoperative position shown inFig. 1.

that there would be an imminent the lower end of the single link, intothe top of the door and thus be danger that would bite forced in thedirection in which the door is moving, causing the device to be brokenor distorted. With the double links this cannot happen. As shown in Fig.3, when the door is stopped in the position shown in Fig. 2, and movedin the direction of the arrow, the lower link will simply assume a morevertical position, raise the upper link and depress the contact bladestill further, until such times as it passes beyond the vertical pointand moves with the door in the direction in which the door is moving.

In the modification shown in Figs. 5, 6 and 7, the contact blade l8 hasbeen placed on the bottom of the bracket, and instead of the upper linkbeing provided with an upwardly extending arm it is bifurcated so as toform a deep slot I9 through which the outer end of the blade l8 passes.When the links are lifted,

as .in Fig. 6,

the lower edge 20 of the slot l9 engages the outer end of the contactblade and forces the blade against the bracket, as plainly shown.

From the foregoing it will be seen that this switch overcomes thedefects found in former switches of this type.

It will also be noted that it is of simple and effective construction,in that, it

causes the contact spring to engage directly with the bracket, thusinsuring a perfect tact.

electric conlar bracket formed from a fiat metal strip and having itsvertical member attachable to the frame of the object on which used; alink hinged to the end of the horizontal member of the bracket andfreely depending therefrom; a second link hinged to and freely dependingfrom the free end of the first link; a contact blade secured to thebracket but insulated therefrom; the second link provided with a detentto cause it and the first link to act as a single lever and to turn uponthe bracket hinge; when moved in one direction, and'to turn upon oneanother and upon the bracket, when moved in the opposite direction; andthe first link adapted to engage the contact blade when the links areoperated as a single lever. V

2. In a switch of the class described; an angular bracket formed from aflat metal strip and having its vertical member attachable to the frameof the object on which used; a link hinged to the end of the horizontalmember of the bracket and freely depending therefrom; a second linkhinged to and freely depending from the free end of the first link; acontact blade secured to the top of the horizontal member of the bracketbut insulated therefrom; the second link provided with a detent to causeit and the first link to act as a single lever and to turn upon thebracket hinge, when moved in one direction, and to turn upon one anotherand upon the bracket, when moved in the opposite direction; and anupwardly extending member provided on the first link for engaging thecontact blade when the links are operated as a single lever.

I 3. In a switch of the class described; an angular bracket formed froma flat metal strip and 'having its vertical member attachable to theupon the bracket hinge, when moved in one direction, and to turn uponone another and upon the bracket when moved in the opposite direction;and a slot formed in the first link the bottom of which engages with thecontact blade when the links'are operated as a single lever.

' Louis LUDWIG.

